Preheat oven to 180 degrees and grease and line 3x8 inch cake tins.
In a large mixing bowl sieve the buckwheat, tapioca starch, cacao powder, baking powder and baking soda. Add in the almond meal and coconut sugar and use a whisk to combine.
1 cup almond meal, ¾ cup buckwheat flour, ¼ cup tapioca starch, ½ cup cacao powder, 1 teaspoon baking powder, 2 teaspoon baking soda, 1 cup coconut sugar
In a medium glass bowl atop a saucepan of hot water, melt the dark chocolate. Remove from the heat and whisk in the olive oil gradually.
90 grams dark chocolate, ⅔ cups olive oil
Add the vanilla extract to the bowl. Add in eggs one at a time, whisking to combine.
3 large eggs, 2 teaspoons vanilla extract
Pour the chocolate mixture into the flour mixture and begin mixing with a handheld beater or stand mixer. Pour the hot water in gradually, while mixing until cake batter is well combined and smooth.
1 cup hot water
Divide the cake batter evenly between the 3 greased cake tins and place in oven to bake for 30 minutes. Once baked and cakes spring back after gently pressing down in the centre, remove from oven and allow to cool in tin for 5 minutes before turning out onto wire rack to cool completely.
Dark Chocolate Ganache
Once cakes are completely cooled it is time to make the dark chocolate ganache. Place a small glass or stainless steel bowl atop a saucepan of water. Bring saucepan of water to a medium heat and add in dark chocolate. Stir frequently until the chocolate is melted. Pour the coconut milk into the melted dark chocolate and whisk until smooth and glossy. Turn heat off and remove ganache from saucepan.
270 grams dark chocolate, 270 mL coconut milk
To make cake, place the first layer onto a cake stand or plate. Place two large spoonfuls of chocolate ganache in centre of cake and spread out evenly with a palette knife.
Place second cake layer on top of the first layer and repeat the previous step.
Place final cake layer on top of the second layer. Spoon another 2-3 large spoonfuls of chocolate ganache mixture spreading out evenly across the top and around the sides of the cake.
Place both the cake and the remaining ganache into the fridge.
Remove the ganache from the fridge after around ten minutes or until ganache is cold and beginning to firm. Beat the ganache with electric beaters until light and fluffy. Transfer to a piping bag with nozzle.
Finish decorating the cake by piping chocolate ganache around the edges of the top of the cake and around the base of the cake.
Store cake in the fridge until ready to serve. Remove from the fridge for 30 minutes prior to serving. After day 2 of storing the cake in the fridge, it is recommended to warm each piece for 30 seconds in the microwave before serving.